diff --git a/packaging/ubuntu_plugin/postinst b/packaging/ubuntu_plugin/postinst
index 412b95fd..25891c76 100755
--- a/packaging/ubuntu_plugin/postinst
+++ b/packaging/ubuntu_plugin/postinst
@@ -1,3 +1,5 @@
+#!/bin/sh
+
 echo "Creating symbolic link for session-manager-plugin"
 if [ -f /usr/local/bin/session-manager-plugin ]
 then
diff --git a/packaging/ubuntu_plugin/postrm b/packaging/ubuntu_plugin/postrm
index fa598641..bbd35ac4 100644
--- a/packaging/ubuntu_plugin/postrm
+++ b/packaging/ubuntu_plugin/postrm
@@ -1,3 +1,5 @@
+#!/bin/sh
+
 if [ -f /usr/local/bin/session-manager-plugin ]
 then
     rm /usr/local/bin/session-manager-plugin
diff --git a/packaging/ubuntu_plugin/preinst b/packaging/ubuntu_plugin/preinst
index 3dbeb1fa..36b8b447 100755
--- a/packaging/ubuntu_plugin/preinst
+++ b/packaging/ubuntu_plugin/preinst
@@ -1 +1,3 @@
+#!/bin/sh
+
 echo "Preparing for install"
\ No newline at end of file
diff --git a/packaging/ubuntu_plugin/prerm b/packaging/ubuntu_plugin/prerm
index 042e7106..1ddc56e5 100755
--- a/packaging/ubuntu_plugin/prerm
+++ b/packaging/ubuntu_plugin/prerm
@@ -1 +1,3 @@
+#!/bin/sh
+
 echo "Start removing session-manager-plugin"
\ No newline at end of file